300 wsm build question

I want to build a 300 wsm for a long range, lightweight(sporter) rifle. I have a winchester pre 64 long action(currently chambered in 30-06). Can I use this action for this build? Or do I need a magnum action?

You can use the action but some modifications will need to be made. First, because it is a pre-64 it is control round feed. You will have to use the magazine, which means you will need to open the feed rails properly to accept the WSM cartridge. Second you will need to open the bolt face up to magum caliber size and instal a magnum claw extractor. You will also need a magazine box with the adapter plate for shorter calibers. None of this is too complicated to do, the magnum claw extractor and magazine box may be the only difficult things to find. Or you can grind back the original claw to make it work and slot the magazine box and make the adapter plate to shorten it. Let me know if you need any help.